I recently watched an academic panel on C-SPAN devoted to “The Worst Presidents In American History.” It was sponsored by the Organization of American Historians.

As is true of so many academic panels today, it was “diverse” in the sense that the participants were of different races and genders. But it was drearily non-diverse in that all the participants were partisans of the political Left. There were no conservatives, libertarians, or moderates on the panel at all.

Predictably, the criteria the panelists identified for determining the worse presidents were similar to those used by academic historians for identifying the best. The most important seemed to be whether the president “made a difference”—that is, changed America in some way—or “achieved his goals.”

But to decide whether a person has done well or poorly in his job, you first need to understand what the job actually is—not what you, or the president, wish the job to be. In other words, you have to know the job description. It is the job description that gives you the factors by which you measure success.

Suppose Jane Smith is the chief accounting officer for a business firm. Does it make her a good chief accounting officer if she dresses well, charms the shareholders, and muscles in on the responsibilities of the board of directors? Obviously not. To determine whether she is a good chief accounting officer, we’ll want to know if she keeps the books efficiently (or hires people who do so), keeps the firm’s tax liability to the legal minimum, and provides wise financial advice.

What is the president’s job description? You can find it in the Constitution. Here are its elements:

* “Faithfully execute the Office . . . and . . . preserve, protect and defend the Constitution of the United States.”
* Sign and veto bills.
* Serve as Commander in Chief of the armed forces.
* Take care that the laws be faithfully executed.
* Grant pardons in certain circumstances.
* With some congressional input, conduct foreign policy. (This is a summary of several more specific powers.)
* Appoint and commission judges and other officers, sometimes subject to Senate approval and sometimes not.
* Nominate a person to fill the vice presidency when there is a vacancy.
* Provide Congress with information on condition of the country.
* Recommend to Congress “such Measures as he shall judge necessary and expedient.”
* In certain circumstances, convene and adjourn Congress.

These elements tell us how to measure a president’s performance. A president performs well if he defends the Constitution, recommends and signs good bills and vetoes bad ones, competently enforces the laws, serves as an effective military leader, appoints appropriate people to office, and conducts a wise foreign policy.

Except as included in those duties, there is nothing on the list about “making a difference” or “changing America” or “achieving one’s goals.”

Thus, if a president recommends or signs a wise measure, he gets points. But if he uses threats and bribes to cram what he wants through Congress, he should get none. Threats and bribes are not part of his job. In fact, they probably are antithetical to the job as the Constitution envisions it.

So what the historians on the C-SPAN panel were doing, as so many others have done, was to judge presidents according to factors irrelevant to his job description—and, in point of fact, created by their own ideology instead.

Next week: Which presidents really were good and bad—judged by the Constitution’s job description.